@CHARSET "UTF-8";
#btn1{
	width:100px;
	height:100px;
	background-color:#ff0000;
}
#btn2{
	width:300px;
	height:300px;
	background-color:#000000;
}
#btn3{
	width:500px;
	height:500px;
	background-color:#0000ff;
}